McPherson introduces a multi mode, transmssion, fluorescence, Raman, microscopy spectrometer as another powerful tool for both research and education. It's basic setup exemplifies both the complexity and the fundamentals of spectroscopy. The system was designed with single beam, f/2 optics to provide optimal energy throughput. The unit is capable of many spectroscopic functions and its compact size (approximately 3 x 4 feet on an optical table) proves ideal for any laboratory setup.
The monochromator component of this system is the Model 272 200mm f/2 instrument. Bilaterally adjustable slit assemblies (vary frm 10microns to 4mm) allow variable bandpass and resolution for measurments. This monochromator was utilized for its throughput; however, the system could be configured including a variety of McPherson higher resolution monochromators like the 350mm 2035.
68 x 68 mm (single grating holder, optional dual-grating turret)
Micrometer adjustable width 0.01 to 4 mm, height settings from 2 to 20 mm
Axial and lateral, with optional port selection mirrors
25-mm, multiply dispersion by the width of your detector for range
Performance with various diffraction gratings:
Grating Groove Density (g/mm)
Spectral Resolution at 312.6nm (nm, FWHM)
Reciprocal Linear Dispersion (nm/mm)
Wavelength Range from 185nm to
First Order Littrow Blaze (nm)
The Fastest and Most Versatile Chamber f/2 optics are employed in this unique sample chamber to direct the beam for transmission, absorption or fluorescence measurements. There are two fluorescence ports positioned in a "T" formation to allow simultaneous measurement of perpendicular or parallel polarized light. Either PMT's or monochromators can be directly attached to each fluorescence port. The sample chamber supports numerous filter holders and polarizer positions. The complete unit including the monochromators and chamber has an optical table and rails. You can do Raman measurements and all elements can be gas purged enabling efficient work in the infrared.
Abstract: Contactless measurements of water temperature are utilized in a number of sciences, such as oceanography, climatology, and biology. Previously reported Raman spectroscopy techniques exploited the changes in the shapes of water Raman bands. Interpretation of these changes is difficult since these bands are composed of multiple lines, each influenced not only by temperature but also by pressure and salinity. This paper presents a proof-of-principal demonstration of a contactless technique which determines water temperature from the ratio of Stokes and anti-Stokes intensities of the water 180 cm1 Raman band. This ratio is not sensitive to pressure and salinity, allowing reliable determination of water temperature.
S. P. Nikitin, C. Manka, J. Grun, and J. Bowles
Abstract: The luminous efficiency and lifetime of plasma display panels (PDPs) are directly related to the performance of phosphors used in PDPs, thus higher efficiency, higher stability against high temperature processes and a long lifetime along with good color chromaticity against vacuum-ultraviolet (VUV) radiation are major concerns in selecting suitable phosphors for PDPs. In the same pursuit, we have developed the nano-sized (15–40 nm) BAM:Eu2+, YAG:Tb3+ and YAG:Eu3+ as blue, green and red phosphors and studied their luminescence properties under VUV excitations. In BAM:Eu2+, the 5d-excitation of Eu2+ ions are found strongly dependent on the crystal field strength and Eu2+ occupy lattice ‘sites I’ by substituting Ba2+ ions. Whereas, in YAG:Tb3+, the observed green luminescence is assigned to 5D4?7Fj transitions (j = 3–6) due to electric dipole–dipole interaction, while, YAG:Eu3+ shows strong red luminescence corresponding to 5D0?7F2 transition. Time evolution studies along with decay time calculations are further employed to verify the sustainable emission without quenching.
Prashant K. Sharma, Ranu K. Dutta, Avinash C. Pandey
Abstract: Porous silicon samples have been prepared from p-type single-crystal silicon <100> by a galvanostatic and an open-circuit etch in 50% HF. The materials display bright red-orange room-temperature photoluminescence (PL) in air and toluene solution. Infrared measurements show that the porous silicon surface is partially oxidized. Exposure to anthracene (An) or 10-methylphenothiazine (MPTZ) results in dynamic quenching of the material's excited state(s). Nanosecond time-resolved PL decays are complex and wavelength dependent, with average lifetimes in neat toluene of 0.3-16 µs. Quenching by An and MPTZ is more efficient and rapid at short observation wavelengths. The steady-state and time-resolved quenching data are well fit to the Stern-Volmer model. The PL decays are well described by a skewed distribution of recombination rates.
Minh C. Ko and Gerald J. Meyer
Abstract: Discussed are the photoluminescence properties of combustion synthesized red and green emitting borate phosphors—YBO3 : Eu3+, BaZr(BO3)2 : Eu3+, YCaBO4 : Eu3+, YAl3(BO3)4 : Eu3+, YAl3(BO3)4 : Tb3+, LaBaB9O16 : Tb3+, LaBaB9O16 : (Ce3+,Tb3+), and Na3La2(BO3)3 : Tb3+-promising for use in plasma display panels and mercury-free fluorescent lamps.
P. A. Nagpure, S. K. Omanwar
Abstract: Coherent anti-Stokes Raman scattering (CARS) with femtosecond interaction pulses has become a popular and powerful spectroscopic method. Non-resonant background is one of the most limiting factors for implementing this method more widely. We propose a new approach that suppresses the non-resonant background contribution to the measured signal in CARS spectroscopy while simultaneously yielding high spectral resolution. The method is based on femtosecond pulse shaping of probe, Stokes and pump beams. Destructive interference suppresses the non-resonant background, resulting only in the resonant contribution being detected.
Stanislav O. Konorov, Michael W. Blades and Robin F. B. Turner
Abstract: We investigate the possibility of implementing coherent anti-Stokes Raman spectroscopy (CARS) with a single laser beam passed through a one-dimensional scattering object. The effect of the random scattering is emulated by shaping the laser pulses with a spectral mask corresponding to the transmission spectrum of a random layered medium. Raman resonances are retrieved through correlation analysis of the CARS spectrum. We study the effect of the scattering parameters on the resolution of the method, and show that improvement of the spectroscopic sensitivity can be achieved by compensating the phase distortions introduced by the scatterer
T.M. Drane, J.W. Hepburn and V. Milner